This research is relevant to pharmacological management of psychiatric disturbance and involves a longitudinal prospective follow up investigation of the parameters affecting the development of dyskinesia symptomatology and clinically diagnosed Tardive Dyskinesia in a large number of subjects exposed to neuroleptic medication. Actuarial estimates indicate a subject load of 1,440 patients entered into the study (15 percent of which will be lifetime neuroleptic free for control-comparison purposes) with objective base line measures of literature suggested potential risk variables being obtained. All subjects will be re-evaluated at 3 month intervals for signs of dyskinesia, extrapyramidal symptoms, and current psychiatric status using objective rating scales. The objective is to increase our understanding of the longitudinal development of neuroleptically induced dyskinesias and to assess empirically the relationship of numerous suggested (but unproven) risk variables to developed symptoms. By focusing on the longitudinal clinical course of early dyskinesia signs we hope to establish an empirical fix on the diagnostic value of these signs as related to early Tardive Dyskinesia thus clarifying an area of current diagnostic confusion and disagreement. Joint but independent ratings and use of videotape technology will aid in more adequate establishment of reliability of dyskinesia assessment. An especially important aspect of this investigation is the initial acquisition and careful periodic prospective updating of psychotropic medication records for all subjects.